Optomechanical system for injecting light, optical coupler of said system illuminating device with said system

ABSTRACT

A system for injecting light, includes an optical coupler having: a lens having a convex entrance face of radial extent R1, a convex central exit face and a peripheral exit face; a cavity, containing the entrance face and with an entrance lateral surface; and a peripheral reflective surface, encircling the lens and the cavity, extending beyond the entrance face; an optical collector, with an entrance, a collecting surface facing the central exit face, and a numerical aperture NA smaller than 1, the collector including a jacket having an end surface; and a member for aligning the optical collector, the optical coupler and the aligning member being integrally formed or being indirectly or directly fastened together, the central distance eF on the axis Oz between the collecting surface and the central exit face being nonzero and smaller than 5 mm, and the system including a stop for the end surface.

This application is a continuation of U.S. application Ser. No.14/908,890, filed on Jan. 29, 2016, which is the U.S. National Stage ofPCT/FR2014/051959, filed Jul. 29, 2014, which in turn claims priority toFrench patent application number 1357461 filed Jul. 29, 2013. Thecontent of these applications are incorporated herein by reference intheir entireties.

The present invention relates to an optomechanical system for injectinglight into an optical medium (guide or extractor), to the opticalcoupler of this system and to an illuminating device with said system.

The invention more particularly relates to an optomechanical system forinjecting light into a thin optical medium, the optical collector ofwhich is formed of a bunch of optical fibers forming a thin injectionribbon for injecting light, especially into a thin light-extractingmedium that is a light-emitting fabric comprising optical fibers.

In the technology of light-emitting fabrics, for example described inpatent FR 2 859 737, illuminating surfaces are produced by weavingorganic optical fibers with textile fibers.

Patent application WO 2007/003857 A, which relates to the field of(advertising) 6-sheets backlit by means of a ribbon of optical fibersable to emit light laterally, describes an optomechanical system forinjecting light.

Such as shown in FIG. 1, the 6-sheet may be very small in thickness. Thefrontside of this 6-sheet therefore comprises an advertising mediumbacklit by a light source. This light source comprises a ribbon ofoptical fibers placed facing the backside of the medium.

Such as shown in FIG. 2, the ends of each of the optical fibers aregathered in a ring tie able to keep each of the fibers in a presetposition relative to the others. The various ring ties are positionedinside a housing formed in a rail. This rail allows the ring ties to bepositioned facing point light sources and, at the same time, the ribbonto be spread. The point sources are arranged on a mechanical carrier.

Such as shown in FIG. 3, substantially reproduced in the presentapplication and renamed FIG. 1, an optical system 11′ concentrates thelight beam emitted by the point source 9′ only in the direction of thering tie 6′. Such an optical system 11′ comprises a centering holder 12′in order to allow the optical system to be put in place on the opticalaxis of the point source 9′ automatically. Moreover, an aligning member20′ allows the ring tie 6′ to be positioned on the optical axis of thesource 9′. Specifically, the aligning member 20′ interacts with ahousing 10′ added to the rail 7′ allowing the ring tie 6′ to bepositioned facing the source 9′. A nut 21′ then allows the ring tie 6′to be immobilized relative to the rail 7′.

However, it turns out that the spatial uniformity of the luminance,which is an important parameter of such luminous surfaces, isunsatisfactory.

Thus, the solution described is not suitable for illuminationapplications, in particular functional illumination applications, thatrequire both a high efficacy and a high uniformity.

The injection system described is also quite bulky and has a complexdesign and is difficult to manufacture.

Therefore, the objective of the invention is to provide a system forinjecting light into a thin optical medium, which system simultaneouslyallows energy efficacy (lm/W), and therefore the light flux incident onthe optical collector (preferably a bunch of optical fibers in a ringtie) and contained in the numerical aperture of the latter, to bemaximized while optimizing the spatial uniformity properties of theinjection, said system necessarily being compatible with therequirements of industry (manufacturing tolerances, cost andsimplicity), robust (mechanical strain impacting optical performance)and as compact as possible (thereby furthermore decreasing the finalbulk of the illuminating device).

Naturally, effective injection of light into the collector, then intothe injection ribbon, and the uniformity of the injection into thecollector, then into the injection ribbon, are two necessary conditionsfor obtaining, in fine, the performance desired for the thinilluminating device:

-   -   optical performance: luminous efficacy especially higher than 40        lm/W in order to work toward illumination that is relatively        energy-efficient relative to the light sources currently        available on the market; to do this, the following will        preferably all be achieved/employed: an injection efficiency of        higher than 40%, a point light source with a luminous efficacy        of higher than 130 lm/W and a light extraction efficiency of        higher than 80%; and    -   quality of the illumination: spatial uniformity of the luminance        of the luminous surface.

For this purpose, the first subject of the invention is anoptomechanical system for injecting light, especially into a thinoptical medium (smaller than 2 cm, and preferably subcentimeter-size, inthickness), the system comprising:

-   -   an optical coupler (able to form a collimator and a concentrator        of light) that comprises (preferably consists of) a (transparent        and preferably axisymmetric) body of (central) axis Oz, O being        the center of the entrance of the optical coupler, including        (preferably consisting of) integrally formed:        -   a lens of (central) axis coincident with the axis Oz, of            preferably subcentimeter-size or preferably millimeter-size            maximum width W, comprising (preferably consisting of):            -   a convex entrance face (which is therefore curved toward                the entrance of the coupler) of radial extent R₁                especially smaller than 5 mm, and preferably larger than                1 mm, said entrance face preferably being axisymmetric                and especially also defined by a central extent, on the                axis Oz, called h_(e);            -   a convex central exit face (which is therefore curved                toward the exit of the coupler), defined by a central                extent, on the axis Oz, called H and preferably smaller                than W, which is especially subcentimeter-size and even                preferably millimeter-size or even more preferably                smaller than 5 mm, and of radial extent R_(A)                (especially smaller than 2.5 mm and preferably larger                than 0.5 mm, said central exit face preferably being                axisymmetric (dome, etc.)); and            -   a peripheral exit face, especially (and preferably)                axisymmetric, that comprises (or consists of) a part                joined to the central exit face, especially of                representative lateral dimension R_(I), said part being                flat (and preferably annular) or concave (curved toward                the entrance of the coupler) or frustroconical and thus                flared in the direction of the exit of the system;        -   a cavity, of (central) axis coincident with the axis Oz, of            central height equal to h_(i), comprising a bottom            containing the entrance face, and a lateral surface, called            the entrance lateral surface, said cavity (of depth h′_(E)            at the junction with the entrance lateral surface)            preferably being axisymmetric and especially frustroconical;            and        -   a peripheral reflective surface encircling the lens and the            cavity, of (central) axis coincident with the axis Oz, able            to totally internally reflect the light rays refracted by            the entrance lateral surface, said peripheral reflective            surface extending beyond the entrance face (therefore beyond            the bottom of the cavity) in the direction of the exit of            the optical coupler, said peripheral reflective surface            preferably being axisymmetric;    -   an optical collector, of (central) axis coincident with the axis        Oz, with as entrance, a surface, called the (light-ray)        collecting surface, facing the central exit face (and at least        the part of the peripheral exit face joined to the central exit        face) of millimeter-size radial extent R_(INT) preferably        smaller than 6 mm, and even smaller than 5 mm, and by a        numerical aperture NA smaller than 1 (preferably smaller than or        equal to 0.6) and comprising a jacket having (as entrance) a        given (so-called) end (also called free) surface, said collector        preferably being axisymmetric, the optical collector comprising        a (circular, hexagonal, etc.) bundle of optical fibers, said        optical fibers having a diameter smaller than 1.5 mm and the        central exit face and the (optically functional) peripheral exit        face being spaced apart from the collecting surface; and    -   a member for aligning the optical collector with the optical        coupler, especially of (central) axis coincident with the axis        Oz and therefore coaxial with the optical coupler, the optical        coupler and the aligning member being integrally formed or being        indirectly or directly fastened together (by a fastening system        preferably attached to or on a carrier of the light source of        the injection system),

the central distance e_(F) on the axis Oz between the collecting surfaceand the central exit face being nonzero and smaller than 5 mm,preferably smaller than or equal to 2 mm, even more preferably smallerthan or equal to 0.6 mm and preferably larger than 0.2 mm,

the optomechanical system (preferably the body of the optical couplerand/or optionally the aligning member) comprising a stop surface againstwhich the end surface abuts.

The optomechanical system according to the invention obtains the bestcompromise between the magnitude and spatial uniformity of the lightflux injected into the numerical aperture of the collecting surface ofthe optical collector, with the aim of making the visual appearance ofthe thin illuminating device as attractive as possible, and allowshigh-power applications and, among the most demanding, functionalillumination applications, to be addressed.

The optical coupler according to the invention is innovative firstlybecause of the design (lens, cavity, peripheral reflective surface) ofthe optical collector of small radial extent (preferably R_(INT) issmaller than 6 mm) and because the light is injected into a thin medium(smaller than 2 cm, preferably smaller than 1 cm in thickness) but alsobecause the optical coupler according to the invention is able tofunction in close proximity to the stop surface, thereby allowing theoptical alignment of the optical collector, which is placed a very smalldistance away from the exit of the lens, to be perfected.

Surprisingly, by virtue of the design according to the invention, W maybe particularly small without generating too many losses.

In the cited prior art, the bundle is not located in close proximity tothe exit face, said exit face furthermore being parabolic and thereforenot having a convex central face. From a mechanical point of view, theoptical alignment is complex because it depends on the peripheral railand requires a housing, the screw fastening is to the side of the ringtie and the lens requires an individual centering holder, and no stopsurface is provided.

According to the invention, the entrance face and the central exit faceare able to orient or maintain (divergent) central light rays (divergentin the sense that they are not precollimated) that are refracted by theentrance face and the central exit face toward or in the numericalaperture NA of the collecting surface of the collector. The peripheralreflective surface and the peripheral exit face are furthermore able toorient or to maintain (divergent) oblique light rays (divergent in thesense that they are not precollimated) refracted by the entrance lateralsurface.

The lens treats the light rays in essentially two different ways:

-   -   central light rays refracted by the bottom of the cavity are        entirely or mainly inscribed in the central exit face of radial        extent R_(A); and    -   oblique light rays refracted by the entrance lateral surface are        then (for the most part) reflected (by total internal        reflection) by the peripheral lateral service and (for the most        part) refracted by the typically annular peripheral exit face of        width R_(A1),    -   thus escape of rays lost beyond the end of the peripheral exit        face at the edges of the stop surface, and for example the        escape of rays lost because not refracted by the peripheral        lateral surface, is minimized.

This separation aims, to a first approximation, to project these twopopulations of central and oblique rays onto two separate zones of thecollector: a central (preferably disc-shaped) surface of radial extentR′A and a (preferably) annular surface of width R′_(A1).

After the optical collector has been placed abutting against the stopsurface, the optical collector is sufficiently close to the exit of thelens, without touching it, for the following relationships to beapproximately respected: R′_(A)=R_(A1) and R′_(A1)=R_(A1).

This conservation of geometric extent is achieved by correctlypositioning the point light source and via its small distance to theentrance face of the lens and to the entrance lateral surface.

Preferably, the light source:

-   -   is Lambertian (in the far field); such as a light-emitting diode        (LED) possessing, in accordance with the nominal Lambertian        source, a viewing angle of 60° (angle at which the light        intensity corresponds to half its peak value);    -   comprises primary optics (preferably a dome);    -   is slightly set back from the entrance of the coupler;    -   has an active zone of width L preferably between 500 μm and 3 mm        and even in a range from 1 to 2 mm; and    -   has a luminous efficacy of at least 130 lm/W.

Without primary optics, the source may get too close to the entranceface.

The light source chosen is preferably polychromatic and especiallywhite. The color of the light emitted is preferably an illuminationbetween 2700K and 8000K, preferably of the “daylight” type at 5500K.

The convexity of the entrance face of the lens contributes to thecompactness of the lens (small height H) above all when the opticalcollector has a very small radius R_(INT).

The convexity of the central exit face allows the light rays to beredressed and maintained in the central region and is chosen dependingon the convex shape of the entrance face.

Moreover, the cavity and the peripheral reflective surface are crucialbecause a simple aspheric biconvex lens would induce a substantial lossof flux, in particular with a Lambertian source (defined as such in thefar field) such as an LED.

The entrance face may preferably have an aspheric surface. The equationof the surface of the aspheric entrance face is preferably written:

${z(r)} = {\frac{r^{2}}{R\left( {1 + \sqrt{1 - {\left( {1 + k} \right)\frac{r^{2}}{R^{2}}}}} \right)} + {A_{4}r^{4}} + {A_{6}r^{6}} + {A_{8}r^{8}} + \ldots}$

where k preferably equals zero.

The optimal coefficients are defined in the following table:

Convex entrance face conical R in constant (k) mm A₄ A₆ A₈ Aspheric 04.50 0.01 −0.001 0 coefficients

The central exit face may preferably have an aspheric surface.

The equation of the surface of the aspheric central exit face ispreferably written:

${z(r)} = {\frac{r^{2}}{R\left( {1 + \sqrt{1 - {\left( {1 + k} \right)\frac{r^{2}}{R^{2}}}}} \right)} + {A_{4}r^{4}} + {A_{6}r^{6}} + {A_{8}r^{8}} + \ldots}$

where k preferably equals zero.

The optimal coefficients are defined in the following table:

Convex exit central face conical R in constant (k) mm A₄ A₆ A₈ Aspheric0 3.00 0 0 0 coefficients

The lens, the cavity and the peripheral reflective surface (and also theoptical collector and even the aligning member) are preferablyaxisymmetric.

To obtain a high uniformity in combination with an optimal efficacy, itmay be desirable to redistribute a fraction of the central and obliquerays, i.e. to direct the central rays toward the peripheral region andthe peripheral rays toward the central region, in order to mix thecentral and oblique rays.

Preferably, the so-called optical point response is used to define thefeatures of the lens so as to obtain this noteworthy opticalperformance.

Thus, the two populations of oblique and central light rays preferablyundergo a certain amount of mixing. More precisely, the optical couplermay preferably have at least one of the following features:

-   -   the bottom of the cavity, the central exit face and the        peripheral exit face are such that, in operation, light rays        refracted by the bottom of the cavity and especially originating        from a point on the axis Oz (preferably within the distance        e_(i), especially slightly larger than h_(e), smaller than 0.5        mm, 0.2 mm for example) are refracted by the peripheral exit        face and thus are deflected away from the axis Oz, rather than        being refracted by the central exit face;    -   and preferably, in operation, light rays, especially originating        from a point on the axis Oz (preferably within the distance        e_(i), especially slightly larger than h_(e), smaller than 0.5        mm, 0.2 mm for example) first refracted by the entrance lateral        surface then on the peripheral reflective surface meet at the        collecting surface in a zone common to light rays especially        originating from a point on the axis Oz (preferably within the        distance e_(i), especially slightly larger than h_(e), smaller        than 0.5 mm, 0.2 mm for example) and first refracted by the        bottom of the cavity (within a distance d substantially equal to        R_(A) of the axis Oz, R_(A)<d<1.5R_(A) for example).

In this preferred embodiment, the peripheral exit face is able torefract and thereby orient or maintain light rays refracted in the(most) peripheral zone of the bottom of the cavity, especially anoptionally flat (annular) part joined to the convex entrance face and/orbordering the convex entrance face, toward or in the numerical apertureNA of the collecting surface of the optical collector.

The optical coupler may preferably have at least one of the followingfeatures:

-   -   if necessary rays (called sacrificial rays) especially        originating from a point on the axis Oz (preferably within the        distance e_(i), especially slightly larger than h_(e), smaller        than 0.5 mm, 0.2 mm for example) refracted by the entrance        lateral surface propagate into the (transparent) body without        encountering the peripheral reflective surface (which is further        down) and do not travel to the exit face of the coupler;    -   if necessary rays (called parasitic rays) especially originating        from a point on the axis Oz (preferably within the distance        e_(i), especially slightly larger than h_(e), smaller than 0.5        mm, 0.2 mm for example) refracted by the entrance lateral        surface then travel to the peripheral exit face and then to the        jacket of the collector, thus preventing rays that lead to        nonuniformities from accessing the collecting surface.

It is desired to couple the light source (preferably an LED lightsource) to the optical collector with the maximum possible efficacy anduniformity.

Regarding the conservation of the geometric extent, if:

-   -   the source is a surface approximated by an emissive disc of        diameter Φ_(s) (for example 1 mm for an LED source) emitting        light into the upper half-space at angles θ1 (for example up to        90° for an LED source) where n is the refractive index of the        primary lens (for example a transparent dome of the LED source)        typically formed by a silicone resin or an epoxy resin;    -   the optical collector arrays a surface of diameter Φ_(int)        (where Φ_(int)=2R_(INT)) having an angular acceptance cone in        air (n′=1) θ′ equal to 30° (numerical aperture 0.5).

Problems with concentrating light flux, i.e. the transformation of asource [aperture 1, angle 1]/collector [aperture 2, angle 2] pair areaddressed by the theorem of conservation of geometric extent:

ϕ_(int) n′ sin(θ′)=ϕ_(s) n sin(θ1)

The minimum area of the collector may then be estimated by thesimplified formula

ϕ_(int)=2nϕ _(s)

namely R_(INT) comprised between 0.75 mm and 2.8 mm for n comprisedbetween 1.5 and 1.6 and Φ_(s) comprised between 0.5 mm and 1.5 mm.

Thus, in a preferred embodiment, R_(INT) is larger than or equal to 1.5mm. Preferably R_(INT) is smaller than 3.0 mm, in a range extending from2.0 mm, preferably from 2.2 mm to 2.6 mm. The smaller the source, suchas a diode (LED), the less the injection of the emitted light into agiven collector will be critical, especially with respect to theposition of the collecting surface of the collector and the exit face ofthe optical coupler (typically adjustment of the alignment along Z andof the central distance e_(f)). The smaller the illuminated surface ofthe collector, the more the illumination of the surface of the collectorwill be intense. A collector of R_(INT) equal to 2.5 mm is thereforepreferable to a collector of R_(INT) equal to 1.5 mm.

For an optical collector of given radial extent R_(INT), an opticalcoupler according to the invention such that:

-   -   1.88R_(INT)<W<3.1R_(INT);    -   0.4R_(INT)<R₁<0.66R_(INT); and    -   0.41R_(INT)<R_(A)<0.68R_(INT)    -   may advantageously be chosen.

Also preferably (in a first embodiment of the peripheral exit face), ifthe part (especially without discontinuity) of the peripheral exit facejoined to the central exit face is flat (especially annular) orfrustroconical (and flared in the direction of the exit of the system)then 0.46R_(INT)<R_(A1)<0.76R_(INT), where R_(A1) is the radial distancebetween A and A1, where A is the lateral end of the exit central faceand A1 the lateral end of the peripheral exit face, especially makingcontact and/or joined to a (frustroconical, annular) ramp leading to thestop surface (at the internal edge B).

In a preferred embodiment, especially for R_(INT) smaller than 3.0 mmand even in a range from 2.2 to 2.6 mm, the optical coupler is definedby the following dimensions:

-   -   W smaller than 10 mm, preferably smaller than 7 mm;    -   H smaller than W, especially H smaller than 4 mm and preferably        larger than 3.6 mm;    -   R_(A) smaller than 1.6 mm, even than 1.5 mm and preferably        larger than 1.2 mm; R1 is smaller than 1.6 mm and preferably        larger than 1.2 mm; and    -   h_(E), maximum depth of the bottom of the cavity smaller than        1.8 mm and preferably larger than 1.4 mm.

Furthermore, it may be preferable for R_(A1) the width of the peripheralexit face to be chosen to be flat (preferably annular) or frustroconicaland smaller than 1.7 mm and preferably larger than 1.3 mm.

Furthermore, the optical system may preferably be defined by:

-   -   e_(F) smaller than 2 mm, even more preferably than 1 mm, and        preferably larger than 0.5 mm; and/or    -   e_(i) distance between O and the light source on the axis Oz        smaller than 0.5 mm and preferably outside of the cavity.

Preferably, the end surface of the jacket extends beyond the internaledge B of the stop surface, B being of radial extent equal to R_(B),therefore R_(INT) is smaller than R_(B).

The end surface faces the peripheral exit face (beyond I, in thedirection away from the center of the coupler).

Furthermore and preferably 0.30R_(INT)<R_(I)<0.60R_(INT) (and/orR_(I)<R_(A)) where R_(I) (lateral dimension representative of theperipheral exit face) is the radial distance between A and I, where I isthe projection (along Oz) onto the peripheral exit face of the internaledge F of the jacket (in other words the external edge of the collectingsurface) and where A is the lateral end of the exit central face.

The stop surface does not make point or linear (circle, etc.) contactbut instead the jacket of the collector bears against it over a certainwidth, preferably of at least 0.2 mm and even at least 0.4 mm.

The stop surface may be manifold and discontinuous, therefore multiplepoints of contact (with a plurality of bearing surfaces preferablyregularly distributed over 360°) or preferably a continuous collar-typesurface, for example. It is preferably axisymmetric.

The (continuous or discontinuous) stop surface may comprise means forfastening or assembling the aligning member with the coupler (when it isdisassociated from the optical coupler).

The stop surface may be flat (and the end surface of the collector ispreferably also flat) and especially annular.

The stop surface may be axisymmetric and is advantageouslyfrustroconical (and flared in the direction of the exit of the system)and the end surface is of complementary shape to the stop surface(beveled external edge, etc.) and especially forms the negative of thefrustroconical stop surface. This system allows the optical alignment ofthe collector to be even further improved by radial centering.

The stop surface, in close proximity to the peripheral exit face, doesnot adversely affect the desired overall uniformity. Preferably, thestop surface does not receive light rays (or receives light rays in anegligible amount) from the coupler.

The peripheral exit face may preferably have at least one of thefollowing features:

-   -   it has no discontinuity (especially vertical discontinuity,        along Oz) or step with the central exit face;    -   it extends sideways further than the entrance lateral surface;    -   it is optionally a surface without an optical texture, such as        for example a Fresnel lens, for design simplicity.

An integral part of the body, the peripheral exit face is preferablymolded (therefore has been demoldable). Preferably, it is not convex.

Regarding the extent of the peripheral exit face, two particular casesare defined:

-   -   first case (already mentioned): the part joined to the central        exit face forms the peripheral exit face, is flat        (notwithstanding optional optical texturing), or frustroconical        (flared in the direction of the exit of the system) and        especially set back from the stop surface, therefore of lateral        end A1, the central exit face in any event preferably protruding        from this joined part;    -   second case: the part joined to the central exit face is concave        and rises continuously (relatively abruptly) as far as the        internal edge B of the stop surface.

The stop surface (of the body or of the aligning member) is preferablyas close as possible to the peripheral exit face (of the end A1 in thefirst case) for example separated by less than 1 mm from the end A1.

A ramp (first case) or a continuous rise (second case, especiallydefined from I as far as B) without an optical role (therefore notserving to refract light rays even when sufficiently collimated in theoptical collector) or at least with a negligible optical role ispreferred.

The ramp is preferably frustroconical, flared in the direction of theexit of the system, especially over a distance that is as short aspossible, preferably smaller than 1 mm.

Naturally, the physical end of the peripheral exit face A1 preferablycorresponds substantially to the end of the optical functionality of theperipheral exit face. This will depend on the entrance lateral surfaceand on the source, especially on its spatial extent, angular propertiesand its radiation (in particular in the near field) and its position onthe axis Oz relative to the cavity.

The transparent body—or even any intermediate adhesively bondedpart—preferably does not comprise a surface adjacent to the peripheralexit face, which would especially be higher up, and not able to form thestop surface because its shape and/or its insufficient height wouldnecessarily lead to contact between the collecting surface of thecollector and the lens.

For the sake of simplicity and optical alignment, the stop surface ispreferably integrated into the body of the optical coupler and is alsopreferably frustroconical.

In the second case the peripheral exit face joined to the central exitface is (slightly) concave, for example defined by a 4^(th) orderpolynomial equation, the central exit face preferably protruding fromthis concave part.

The peripheral reflective surface gets further away from the entrancelateral surface and from the entrance face in the direction of the exitof the coupler and:

-   -   is preferably of maximum extent z_(D) along Oz larger than H/2        (in order not to lose too many rays) and preferably smaller than        the minimum extent z_(A) of the collimating face and/or than the        minimum extent of the peripheral exit face;    -   and/or preferably the minimum distance hm, called the minimum        material entrance distance, between the peripheral reflective        surface and the peripheral exit face is larger than 0.8 mm (and        even if possible the minimum distance between the peripheral        reflective surface and the stop surface if integrated into the        coupler is larger than 0.8 mm), in order to facilitate the        injection of the hot plastic (preferred material of the lens) if        needs be;    -   and/or is preferably of radial extent R_(D)>R_(INT) (more        preferably R_(D)>R_(A1), even R_(D)>R_(B)) and R_(D)>1.3R_(INT)        where D is the physical limit of the peripheral reflective        surface, preferably defining the width W (equal to 2R_(D)), or        at least the limit of the optically functional surface of the        peripheral reflective surface.

The peripheral reflective surface may furthermore preferably have atleast one of the following features:

-   -   it has an external surface that does not make optical or even        mechanical contact (free surface) and/or that is untreated;    -   and/or it starts from the end of the entrance lateral surface or        is separated by an (annular) flat from the entrance lateral        surface;    -   and/or it is a continuous surface, without discontinuities or        without “splines” such as defined in patent application WO        2009/064275 for example.

The peripheral reflective surface may preferably have an asphericsurface. The equation of the aspheric peripheral reflective surface ispreferably written:

${z(r)} = {\frac{r^{2}}{R\left( {1 + \sqrt{1 - {\left( {1 + k} \right)\frac{r^{2}}{R^{2}}}}} \right)} + {A_{4}r^{4}} + {A_{6}r^{6}} + {A_{8}r^{8}} + \ldots}$

where k is preferably equal to −1.

The optimal coefficients are defined in the following table:

Peripheral reflective surface conical R in constant (k) mm A₄ A₆ A₈Aspheric −1 1.25 −0.00569 0.0001373 0.00002663 coefficients

The entrance lateral surface allows oblique rays to be refracted andthus a substantial part of the oblique light emitted by the (preferablyLED) source to be collimated. It is not enough to associate a centrallens having a convex entrance face and a flat central exit face becausethe distribution of the light concentrated on the collector is then notuniform enough on the surface of the collector.

The entrance lateral surface may preferably have at least one of thefollowing features:

-   -   it is demoldable (surface containing at least one hollow to be        avoided);    -   it is preferably frustroconical over at least one (first)        surface portion closest to the bottom of the cavity, said        portion being flared in the direction of the entrance of the        coupler, said first surface portion preferably being extended by        one or more other frustroconical portions that are flared in the        direction of the entrance of the coupler;    -   it is of radial extent R_(C)>R₁ and preferably R_(C)>R_(A),        where C is the lowest point in the cavity (of extent in z equal        to 0).

Peripheral peaks on the illumination map are decreased as well as can beby inclining (at least) this surface portion closest the bottom of thecavity, called the first frustroconical portion. As a variant, thisfirst portion may be cylindrical.

Provision may be made for:

-   -   a second frustroconical portion, preferably higher (along z)        than the first portion, having a second inclination, relative to        the axis Oz and with distance from the entrance face, which is        smaller than the first inclination (slope at least 5 times and        preferably better still 8 times lower) and flared in the        direction of the entrance of the coupler;    -   and optionally, for purposes of mechanical protection, a third        (shorter) frustroconical surface portion flared in the direction        of the entrance of the coupler, having a third inclination and        preferably extending as far as the end of the peripheral        reflective surface.

Over all the surface portions, the differences between each slope andthe slope of the line passing through the 2 end points of thelongitudinal cross section of the entrance lateral surface is preferablysmaller in absolute value than 2° and the associated standard differenceis preferably smaller than 10°.

Preferably, if the light source is equipped with a primary dome thelatter is mainly inserted into the cavity.

For example, the distance between the surface of the dome and theentrance lateral surface is larger than 100 μm and is smaller than 500μm.

For example, the distance between the surface of the dome and theentrance central face is larger than 100 μm and smaller than 300 μm andpreferably smaller than or equal to 200 μm.

Preferably, the (almost point) light source, such as a diode, isLambertian in the far field and is comprised between 500 μm and 2 mm inextent, for example 1.5 mm.

The entrance central face preferably forms at least 90% of the bottomand may optionally be extended, preferably without a step/discontinuity,by a flat (preferably annular) peripheral entrance face, of width R′₁smaller than 0.5R₁ even than 0.1R₁. This optional flat between theentrance face and the entrance lateral surface for example serves toredirect light rays originating from a source on the axis Oz toward theperiphery of the illumination map.

The optical coupler may consist only of a transparent and preferablyplastic material, especially PMMA (polymethyl methacrylate) andpreferably PC (polycarbonate) which is less brittle. It may thereforepreferably be molded, for ease of industrialization.

Injection molding is a process that employs thermoformable materials andnotably thermoplastics. Most thermoplastic parts are manufactured withinjection presses: the plastic is softened then injected into a mold,and then cooled. Injection molding is a technique used for large-scaleor very large-scale mass production of parts. It is above all used withplastics and elastomers (rubbers). Contrary to other processes in whichthe mold is discarded after use (sand molding, disposable wax moldingetc.), care is taken to ensure that the injected parts do not gettrapped in the molds and that they can in contrast be demolded withoutdegradation. This is the reason why surfaces that are not very large arenot parallel to the extraction direction, but differ therefrom by asmall angle called the “draft” angle.

The dimensions of the design of the optical coupler (and/or the aligningmember) preferably meet constraints related to the injection moldingstep. They mainly aim to facilitate the injection of the hot plastic(thus h_(m)>0.8 mm) and demolding (entrance angle β>2° and exit angleβ′≥20°). Moreover, it will again be noted that hollow optical shapes arenot producible with the injection-molding technique.

Thus, the minimum draft must preferably be larger than 0° and preferablyat least 1° and even at least 3°.

The refractive index of the optical coupler is typically 1.5 at 550 nm.

According to the invention, the expression “millimeter-size” isunderstood to mean a value lower than 10 mm and of at least 1 mm.

According to the invention, the expression “submillimeter-size” isunderstood to mean a value lower than 1 mm.

According to the invention, the expression “subcentimeter-size” isunderstood to mean a value lower than 1 cm.

The optical collector and the aligning member are securely fastened. Theuse of additional fastening rails taking the form of a bulky and complexperipheral frame as in the prior art is preferably avoided.

The optical collector is preferably directly assembled, preferablymechanically, (fitted) into the aligning member, which is located inclose proximity to the peripheral exit face and/or the stop surface. Theoptical collector is held by its jacket in the aligning member and maybe easily fitted and demounted.

The aligning member is preferably directly assembled to the coupler,preferably mechanically, or even forms part of the coupler (a monolithicpart), and, lastly the coupler is added and fastened via a printedcircuit board (PCB) carrier, bearing the almost point light source suchas a diode (LED).

The aligning member is for example securely fastened to the opticalcoupler by fastening means (mechanical means such as a flange(s), ascrew, clip fastening means, snap fastening means, by force-fitting oreven magnetic or adhesive bonding means), said means being integratedinto the stop surface belonging to the coupler or into a surface of thecoupler removed from the stop surface and optionally closer to theentrance of the coupler.

Alternatively, the optical coupler is preferably directly assembled tothe aligning member (which incorporates the stop surface), and lastlythe aligning member is added and fastened via a PCB carrier (andaligned) bearing the almost point light source such as a diode (LED).

For example, the coupler incorporates mechanical fastening means such asnotches, clip-fastening means, clamping ribs, force-fitting means oreven magnetic or adhesive bonding means in a dedicated part of thecoupler (“lobe”, flank) that is preferably located above the peripherallateral surface and below the stop surface belonging to the aligningmember (connection therefore closer to the entrance of the coupler)and/or below the peripheral exit face (or in its lateral extension).

The aligning member may preferably have at least one of the followingfeatures:

-   -   it is made of plastic (molded, etc.) especially of transparent        or opaque polycarbonate (PC) and especially of the same        material, or at least of a material having the same thermal        expansion coefficient, as the coupler; and    -   in particular is integrally formed with the coupler,    -   and for assembly with the optical coupler, it preferably has at        least one of the following features:    -   a variable lateral dimension (typically diameter) that increases        with Z (with distance from the coupler);    -   it comprises clamping ribs or means for fitting the optical        coupler, such as bayonets or force-fitting means; and    -   it encircles the jacket in a first region (especially a crimped        region of the jacket) and clamps it in a second region called        the clamping zone (demountable fitting) of sufficient length to        ensure the collector is mechanically fastened and aligned.

For example, the optical collector has a circular or hexagonal crosssection and the aligning member is a cylinder. As a variant, if thecollector is square, then the aligning member is a rectangularparallelepiped of square cross section.

The collecting surface of the collector is preferably flat and polished.

Also, for compactness and to make fitting and optical alignment easier,in a preferred embodiment:

-   -   the aligning member, which is preferably axisymmetric and of        axis coincident with the axis Oz, houses the optical collector        (inclusive of jacket) that itself is preferably axisymmetric and        preferably a bunch of optical fibers; and    -   the body and/or the aligning member incorporates the stop        surface;    -   and preferably the body incorporates the aligning member.

It is preferable to incorporate the body (the optical coupler) into thedesign of the aligning member if possible, for a number of reasons:

-   -   the latter are very small in size (especially the coupler)        therefore it is difficult to incorporate fastening tabs (for        clip-fastening for example) into the system;    -   the fastening, for example clip fastening, requires mechanical        connections to be present, these connections being less strong        than a monolithic structure, especially if the fastening is        subjected to substantial stresses, for example those that may be        applied during fitting and demounting operations;    -   it is necessary to develop two parts and therefore two molds        leading to a higher tooling cost and a longer development time.

An alternative route at least allowing optical performance to bemaintained, even if it is a less preferred route, consists nonethelessin using two independent parts, the optical coupler and the aligningmember, said parts preferably being centered (along the axis Oz) andaligned with each other via an interaction between the (PCB) sourcecarrier and at least (and preferably only) the optical coupler, andimmobilized along Oz by fastening to the (PCB) source carrier.

The injection system may comprise an (almost point) light source,especially a light-emitting diode (LED):

-   -   of small thickness smaller than 2 mm, package and primary optics        optionally included;    -   the emissive zone of which is centered on the axis Oz and placed        at a distance e_(i) on the axis Oz smaller than 0.4 mm under the        center O of the entrance of the coupler;    -   with a subcentimeter-size or even submillimeter-size base (or        package) made of plastic, for example of FR-4, or of a        ceramic—the base itself resting on and being electrically        connected to a (generally flat, flexible or rigid) source        carrier that is preferably a printed circuit board (PCB) carrier        that is for example made of FR-4 or a metal such as aluminum.

The optical coupler preferably incorporating the aligning member maythus rest on the printed circuit board (PCB) carrier, via one or morebearing surfaces of the coupler, preferably protruding relative to thecavity, said bearing surface(s) being spaced apart from the peripheralreflective surface—leaving a gap between the entrance O of the couplerand the (PCB) source carrier, (and even the source).

The optical coupler preferably integrating the aligning member may besecurely fastened to the (PCB) source carrier; preferably the (PCB)source carrier and one or more (lateral) zones (especially lateral tothe peripheral reflective surface) of the coupler, especially protrudingrelative to the cavity, comprise complementary (male/female,force-fitting) assembly means thus forming a system (blocking laterallyand roughly along Oz) for self-centering the almost point source withthe optical coupler, and optionally additional locking means (blockingalong Oz).

If not, the optical coupler may be (securely fastened) assembled in thealigning member that rests on the (PCB) source carrier and is securelyfastened to the (PCB) source carrier. Preferably, one or more areas ofthe aligning member and the (PCB) source carrier comprise complementary(force-fitted male/female) assembly means thus forming a system forself-centering (blocking laterally and roughly along Oz) the almostpoint source (diode) on the optical coupler, and optionally additionallocking means (blocking along Oz).

For example, the complementary assembly means comprise at least two malemembers such as tenons on two bearing surfaces of the coupler or of thealigning member bearing the coupler (backside of two fins preferablyaligned on either side of the lens), said tenons being fitted (inserted)into the (PCB) source carrier that is apertured for this purpose (blindor through-holes at least forming two female members). For example, moreprecisely, at least two tenons on two bearing surfaces of the coupler orof the aligning member bearing the coupler (backside of two finspreferably aligned on either side of the lens) are force-fitted byvirtue of their conical shape into the (PCB) source carrier that isapertured for this purpose (blind or through-holes). To within themanufacturing tolerance (for example ±100 μm), the diameter of theaperture in the source carrier is adjusted so that it corresponds to thelower diameter of the tenon. As the upper diameter of the tenon isslightly larger, this rightly allows the coupler or aligning member tobe force-fitted into the source carrier.

Thus, exact self-centering of the three elements: the light source suchas an LED, the optical coupler and the optical collector in the aligningmember, is guaranteed. Furthermore, at the moment of fitting, thecomplementary assembling means prevent lateral movement of the entrancelateral surface from deteriorating the light source (diode).

Preferably a single injection molding operation is used to manufacturethe entire system: optical coupler—aligning member of thecollector—bearing zones and/or zones for fastening to the carrier and/orfor centering relative to the light source.

It is desirable for each part of the system made up of the aligningmember and collector, coupler and board (PCB carrier) to be easy toconnect/disconnect.

The PCB carrier may itself be located on a heat sink such as a metalplate, especially made of aluminum. The optical coupler with the heatsink may be housed in a preferably metal housing comprising an aperturethrough which a part of the optical collector (bundle) is able to pass.

It is desirable for the grip of the aligning member on the collector tobe sufficiently firm that the latter cannot be unintentionallydeconnected, for example when a mechanical stress is applied to the(PCB) source carrier. The gripping force may be adjusted by adjustingthe thickness of the ribs and/or by adjusting the outside diameter ofthe jacket.

Naturally, the invention also aims to protect key parts of the inventionthat are integratable into the aforementioned injection system.

Thus, one subject of the invention relates to the assembly comprisingthe optical coupler and the aligning member of the optomechanical systemsuch as described above, said optical coupler and aligning member beingsecurely fastened or able to be securely fastened (before fitting) oroptionally forming a single part, the body or aligning memberincorporating the stop surface against which the aforementioned opticalcollector bears.

Naturally, the optical coupler, like the aligning member, comprises theaforementioned preferred elements for centering and fastening to thesource carrier and for fitting/demounting the optical collector in/fromthe aligning member.

Another subject of the invention relates to the optical coupler of theoptomechanical system such as described above (alone), the bodypreferably incorporating the stop surface against which theaforementioned optical collector is able to bear.

Although less preferable, the optical coupler could be used in analternative optomechanical injection system differing in that the endsurface is not placed in abutment (the collecting surface nonethelessremains at e_(F) and therefore near the central exit face). Thus, thesystem (coupler) will not comprise a stop surface.

Naturally, the optical coupler may comprise the aforementioned preferredelements for centering and fastening to the source carrier.

The optical collector according to the invention may preferably have atleast one of the following features:

-   -   it may comprise the (circular, hexagonal, etc.) bundle of        optical fibers with optical fibers of diameter preferably        smaller than 1 mm, even smaller than 750 μm; and    -   it may have a jacket that is a metal ring crimped (preferably        over at least a distance of 4 mm and at most 8 mm) then not        crimped (preferably over at least a distance of 3 mm and at most        6 mm) gathering and gripping the ends of the (circular,        hexagonal) bundle of optical fibers, the optical fibers        organizing into at least one injection ribbon and especially        then opening onto an preferably thin light-extracting medium.

The collector may comprise optical fibers (in the preferably crimpedjacket) that may, independently or in totality, preferably have at leastone of the following features:

-   -   being of submillimeter-size diameter, especially 750 μm diameter        and better still of a diameter smaller than 750 μm, preferably        of 200 to 550 μm and more preferably of about 500 μm (typically        between 470 and 530 μm) or even 250 μm;    -   being of average power per fiber preferably comprised between        0.35% and 0.46% of the flux emitted by the (LED) source for        fibers that are about 500 μm (typically between 470 and 530 μm)        in diameter, or of average power per fiber between 0.075% and        1.35% of the flux emitted by the (LED) source of diameter        between 250 μm and 750 μm;    -   being of circular, even substantially circular, even hexagonal        or even partially circular and partially hexagonal cross        section, especially in a crimped zone of the jacket; and    -   being chosen to be identical.

The optical fibers may be formed of a mineral or organic materialcomposing the core of the optical fiber. The mineral materials for thecore are for example chosen from the group comprising glass, quartz andsilica. Organic materials for the core are for example chosen from thegroup comprising polymethyl methacrylate (PMMA), polycarbonate (PC),cyclo-olefin polymers (COPs) and fluoropolymers. The optical fibers mayhave a core (light guide) covered with a cladding of refractive indexlower than that of the core and that may be of different nature. By wayof example of particularly suitable core-cladding fibers, mention may bemade of fibers comprising a core made of polymethyl methacrylate (PMMA)and a cladding based on a fluoropolymer such as polytetrafluoroethylene(PTFE). When the fibers used are core-cladding fibers the thickness ofthe cladding may be comprised between 2 and 15 μm and preferably between5 and 10 μm.

The jacket may entirely encircle (preferably especially annular orfrustroconical surface) or even encircle sections of (each section beingannular or frustroconical, etc. forming a hoop, etc.) the collectingsurface (the collecting part) of the collector.

A metal jacket (for example made of aluminum), drawing the opticalfibers together onto a (substantially) circular surface of R_(INT) ofabout 2.5 mm, and optical fibers (synthetic optical fibers for example)of 500 μm diameter having a numerical aperture of 0.5 (an angularacceptance of) 30° are preferred. Furthermore, each collector (bundle)contains at least 70 fibers, even 75 optical fibers.

If the number of optical fibers is decreased, R_(INT) may be decreasedand a “sacrificial” ring may preferably be added in order to maintaincrimping for a radial extent of about 2.5 mm.

The injection system according to the invention may comprise a (thin)optical guide, preferably directly at the exit of the jacket and then anilluminating device may comprise the injection system and a (thin)light-extracting medium. At least one injection ribbon preferably madeof optical fibers (especially consisting of optical fibers), especiallymade up of one or two layers, and even a light-extracting mediumcomprising light-extracting optical fibers, is preferably used.

Even more preferably, the injection ribbon is made of optical fibersoriginating from the optical collector (which is a bundle) and thelight-extracting medium indeed comprises these optical fibers which arethen light extractors.

The injection ribbon made of optical fibers according to the inventionmay preferably have at least one of the following features:

-   -   the injection ribbon comprises a single layer of optical fibers,        said fibers being optically independent (little or no cross        coupling), or two layers, for example in order to emit flux via        two main faces of the extracting medium; and    -   the injection ribbon has a thickness smaller than 5 mm and        better still smaller than 1 mm, preferably corresponding to the        diameter of the optical fibers.

The fibers of the injection ribbon (in a given layer) are typicallyregularly spaced, with a distance between them (center to center)preferably comprised between 0.3 mm and 2 mm and a separation distance(empty space between fibers) preferably between 0.15 mm and 2.2 mm.

Otherwise, in a preferred embodiment, the optical collector preferablycomprises a bundle of optical fibers, said optical fibers having adiameter smaller than 1.5 mm, the optical fibers organizing at the exitof the jacket into at least one thin injection ribbon, especially ofthickness smaller than 2 mm, opening onto a thin light-extracting mediumof thickness smaller than 5 mm.

Of course, the source carrier (large enough for this purpose, preferablyan LED PCB carrier) may bear a plurality of injection systems, such asthe aforementioned, said systems being located side-by-side, preferablyidentical and leading to a plurality of injection ribbons (preferablymade of optical fibers), (able to be) optically coupled to an edge faceof a light-extracting medium. Furthermore, the number of injectionsystems, such as the aforementioned, may be increased or doubled byadding injection systems on an opposite edge of the extracting medium.

As the, preferably thin, light-extracting medium, a light-extractingelement formed of a ribbon of optical fibers made extractive(sandblasting, laser, etc.) and/or a light-extracting transparent orsemitransparent film, especially a film that scatters light in its bulkor its surface, is preferred.

A woven textile is a sheet, obtained by weaving or knitting, made up ofdirectionally distributed fiber-based threads. The weaving is the resultof the interlacing, in a given plane, of threads arranged in the warpdirection (called warp threads below) and threads arrangedperpendicularly to the warp threads, in the weft direction (called weftthreads below). The binding obtained between these warp threads andthese weft threads is called the weave. The binding threads ensure thesatisfactory cohesion of the woven textile and, depending on theirnature, their size and/or mechanical properties, determine theparticular properties of the textile.

Now, light-emitting fabrics currently exist comprising a woven textileobtained by weaving threads, called binding threads, and optical fibers.The term “binding thread” encompasses all threads or fibers other thanoptical fibers, i.e. any thread or fiber not having the property ofbeing able to emit light laterally, and therefore any thread or fibernot directly connected or connectable to the injection system.

A light-emitting fabric and its weaving method are for example describedin document FR 2 859 737 or WO 2005/026423 and adhesive bonding to arigid carrier in FR 2 907 194 or its arrangement on a rigid carrier indocument FR 2 938 628 (all the examples) or in the aforementioned priorart WO 2007/003857 (FIGS. 1 and 2).

These known light-emitting fabrics preferably comprise woven textileswith:

-   -   binding threads comprising synthetic polymer fibers of organic        nature such as polyester or polyamide fibers; and    -   optical fibers of organic nature.

More widely, the following may be chosen:

-   -   binding threads comprising organic fibers of natural, animal or        vegetable origin, such as silk, wool, cotton, flax or hemp;    -   binding threads comprising organic fibers containing natural or        synthetic polymers such as cellulose, polyamides, polyesters        such as polyethylene terephthalate (PET) polybutylene        terephthalate (PBT), polyvinyl chloride (PVC), polyolefins such        as polypropylene (PP) and polyethylene (PE) and polyacrylics        such as polymethyl methacrylate; and    -   fiber blends.

Advantageously, the woven textile according to the invention maycomprise binding threads containing mineral fibers, and especiallycomprises by weight relative to the weight of the woven textile at least20%, at least 30%, at least 40%, at least 50%, at least 60%, at least70%, at least 80%, or at least 90% of compound of mineral nature.

The optical fibers of the woven textile comprise invasive alterations,corresponding to notches or small slits, that allow light to beextracted from the fibers because they modify the angle of reflection ofthe light rays inside the fiber and the lateral transmission of thelight to the exterior of the fiber. The optical fibers therefore make itpossible both to convey light inside their structure but also to emitlight laterally. Therefore, the optical fibers allow light to be guidedand distributed inside the light-emitting fabric and the main surfacesof the light-emitting fabric to be illuminated diffusely.

The invasive alterations may be obtained in various ways and especiallyby abrading processes such as sandblasting or ablation by means ofhigh-intensity light beams such as a laser beams. The invasivealterations may be produced in the optical fibers before or afterweaving. The invasive alterations may be produced in only one surfaceportion of the fiber or on two opposite surface fractions of the fiber.

The woven textile may comprise two groups of optical fibers, one groupabraded in a surface fraction oriented toward a first main face of thetextile, the other group being abraded in a surface fraction orientedtoward the opposite main face of the textile. These groups maypreferably be in separate regions, adjacent regions or in a commonregion.

The, especially thin, light-extracting medium of the illuminating deviceaccording to the invention may therefore preferably be chosen from atleast one of the following elements:

-   -   optical fibers (preferably) of at least one injection ribbon        made of optical fibers preferably originating from the        collector, the surface of said optical fibers being abraded in        order to scatter light, said fibers optionally at least        partially in or on a transparent or semitransparent (for example        translucent) material (or matrix), especially glass or plastic,        said material preferably having a refractive index (at 550 nm)        that differs by at least 0.05 or even 0.1 from the refractive        index of the cladding of the optical fiber composed of a core        encircled by a cladding;    -   a light-emitting fabric including (preferably consisting of) a        woven textile comprising optical fibers woven into a textile,        said optical fibers (preferably) belonging to at least one        injection ribbon made of optical fibers preferably originating        from the collector, the surface of said optical fibers being        abraded in order to scatter light, said fabric optionally being        associated with a sheet of glass or plastic or being located        between two glass sheets (preferably via lamination interlayers,        for example made of polyvinyl butyral (PVB), ethylene vinyl        acetate (EVA) or polyurethane, or even via a resin or any other        bonding means etc.) or between two plastic sheets or even a        glass sheet and a plastic sheet;    -   at least one transparent or semitransparent sheet or film,        especially made of glass and/or plastic, coupled (via its edge        face) to an injection ribbon made of optical fibers, originating        from the collector, said, preferably thin, film comprising means        for scattering light.

The aforementioned extracting elements may of course be combined(juxtaposed or even superposed).

By way of preferred thin extracting media, mention may be made oflight-emitting fabrics preferably produced in Lightex® technologyespecially by Brochier. The light-emitting fabric may be white, coloredand patterned or unpatterned. The light-emitting fabric may be:

-   -   uniform with a standard textile weave;    -   decorative with a geometric or figurative pattern created in the        woven textile (jacquard pattern) of by reworking a uniform        textile;    -   informative with a logo, a message, an identity or a sign.

The light-emitting fabric makes it possible to produce light over partor over all its surface.

In particular, by way of light-extracting media (of the semitransparentor transparent film or sheet type) mention may also be made of:

-   -   plastic film(s) and preferably ETFE (ethylene        tetrafluoroethylene) or FEP (fluorinated ethylenepropylene)        film(s) comprising means for scattering light;    -   a glass sheet (preferably as inabsorbent as possible, for        example made of clear or extra clear glass, etc.) of thickness        smaller than 3 mm or even smaller than 1 mm, preferably a single        glazing unit, said sheet(s) comprising means for scattering        light.

Light is extracted (from the thin medium) optionally via an added and/orremovable layer (making optical contact with a transparent material forexample and/or with the optical fibers preferably belonging to theinjection ribbon).

In particular, the semitransparent or transparent film or sheetcomprises, as means for scattering light, a scattering layer depositedon one main face, for example a layer with a (typically polymer ormineral) matrix containing scattering elements (of refractive indexdifferent from the index of the matrix, for example by at least 0.1)that are conventionally (preferably mineral) particles.

Light is typically extracted (from the thin medium) via surfacescattering (textured, abraded surface, etc) and/or by internal (laser)etching.

In particular, the semitransparent or transparent film or sheet maycomprise, as means for scattering light, a textured, irregular or roughsurface or internal etching. This is typically produced by (mechanical,etc.) abrasion or by a chemical etching.

The light-extracting medium may be made up of a number of layers.Provision may be made to assemble (laminate) one of the aforementionedelements, in particular laminated glass sheet, glass/plastic bilayer,optical fiber textile and glass sheet as described in patent applicationWO 2008/062141.

The light-extracting medium may be any shape (with corners, rounded,etc.).

Another example of a light-extracting medium is formed by a fibrousstructure preferably chosen from at least one of the following elements(alone or in combination): a mat of especially glass or silica fibers orof (organic) synthetic or natural fibers or a woven, nonwoven or knittedtextile. This fibrous structure may especially be applied to a main faceof a glass or plastic sheet. Such an extracting medium is described inpatent application WO 2012/098330, in particular in its examples and onpage 12 to page 14. These nonwoven or woven textiles comprise mineral ororganic, natural or synthetic fibers (or threads). These fibers may bechosen from:

-   -   mineral fibers such as glass or basalt fibers;    -   organic fibers of natural, animal or vegetable origin, such as        silk, wool, cotton, flax or hemp;    -   organic fibers comprising natural or synthetic polymers such as        cellulose, polyamides, polyesters such as polyethylene        terephthalate (PET) and polybutylene terephthalate (PBT),        polyvinyl chloride (PVC), polyolefins such as polypropylene (PP)        and polyethylene (PE) and polyacrylics such as polymethyl        methacrylate; and    -   fiber blends.

Here, the nonwoven textile is a sheet made up of directionally orrandomly distributed fibers that have not been woven (or even knitted)and the internal cohesion of which is ensured in various ways such as bymechanical, physical or chemical methods and/or by combining thesevarious methods.

If the extracting medium is thicker than the injection ribbon—especiallywhen it is not a fabric using optical fibers belonging to the injectionribbon—a thickness difference smaller than 5 mm and preferably smallerthan 3 mm is preferred.

The injection ribbon preferably made of optical fibers may be:

-   -   adhesively bonded to the edge (edge face) of the extracting        medium, especially when it is not a fabric using optical fibers        belonging to the injection ribbon;    -   or better still, inserted into a transition medium of refractive        index near or identical to that of the extracting medium        (refractive index difference preferably less than 0.1 at 550 nm)        and/or inserted into the extracting medium.

The distance between the end surface of the collector and the extractingmedium is for example comprised between 5 and 15 cm.

The illuminating device may comprise a carrier preferably chosen from:

-   -   a suspending system (hanger, etc.) from which the        light-extracting medium is suspended;    -   a scaffold (frame etc.) over which the light-extracting medium        is hung; and    -   a board (the term being used with a broad meaning and for        example encompassing films and panels) to which the        light-extracting medium is added, even fastened (preferably        adhesively bonded).

The board may be:

-   -   transparent, translucent, semitransparent, colored (preferably        white), reflective, opaque (absorbent), fluorescent, and/or    -   of preferably flat or even curved general shape,    -   and/or flexible and preferably rigid,    -   and/or thermally conductive or thermally insulating,    -   and/or of any thickness.

Mention may in particular be made by way of boards (the term being usedwith a broad meaning) of:

-   -   a plasterboard;    -   a (flat or curved) metal element taking the form of a wall        lining for example; and    -   a living space element or an element integratable into a living        space.

The present invention will be better understood on reading the detaileddescription below of nonlimiting example embodiments and by way of theappended drawings, in which:

FIG. 1 illustrates a conventional optomechanical system for injectinglight;

FIG. 2 illustrates a partial longitudinal cross-sectional view throughan optomechanical system according to a first embodiment of theinvention;

FIG. 3 illustrates a detail view of FIG. 2;

FIG. 4 illustrates a partial longitudinal cross-sectional view throughthe optomechanical system of the first embodiment of the invention(without the light source on its carrier);

FIG. 5 is a top view of the optomechanical system (without the opticalcollector) of the first embodiment of the invention;

FIG. 6 illustrates the centered point response of the optical couplerbased on twelve light rays spaced apart by 7° and emitted from acentered point source;

FIG. 7 shows the path of a few representative light rays originatingfrom a centered point source;

FIG. 8 shows a map of illumination at the collecting surface of thecollector, and two orthogonal cross sections through the illuminationmap;

FIG. 9 illustrates a partial longitudinal cross-sectional view throughan optical coupler of an optomechanical system according to a secondembodiment of the invention;

FIG. 10 illustrates a view of the entrance of an optical coupler of anoptomechanical system according to a third embodiment of the invention;

FIG. 11 illustrates a partial cross-sectional view through theoptomechanical system of the third embodiment the invention; and

FIG. 12 illustrates a partial cross-sectional view through theoptomechanical system of a fourth embodiment of the invention.

FIG. 2 (and FIG. 3 which is a detail view) illustrates a partiallongitudinal cross-sectional view through an optomechanical system 1000,for a thin optical medium (preferably an injection ribbon coupled to alight-emitting fabric), according to a first embodiment of theinvention, the system comprising an optical coupler 1 that comprises atransparent body made of PMMA (polymethyl methacrylate) of optical indexn=1.5895 at 550 nm, which is obtained by molding, said coupler beingaxisymmetric and of central axis Oz, shown and clearly defined in aplane (O, X, Z) corresponding to the plane of the longitudinal crosssection, O being the center of the entrance of the optical coupler 1.

FIG. 3 shows the outline of each surface of the optical coupler in thelongitudinal cross-sectional plane and representative points are definedfor each portion, only in the positive quadrant of the cross-sectionalplane for the sake of clarity.

The optical coupler 1 comprises:

-   -   a lens 10 of central axis coincident with the axis Oz, here        axisymmetric, and comprising:        -   a convex entrance face 11, defined by a central extent, on            the axis Oz, called h_(e), and of radial extent R₁, said            face 11 having a peak E (0, h_(e)) and a circular end            outline (external perimeter) passing through the end E1 (R₁,            z_(E1));        -   a convex central exit face 12, defined by a central extent,            on the axis Oz, called H, and of radial extent R_(A), said            face 12 having a peak S (0, H) and a circular end outline            (external perimeter) passing through the end A (R_(A),            z_(A)); and        -   a peripheral exit face 13, joined to the central exit face            12, preferably without discontinuity, said face 13            preferably being flat (or, as a variant, frustratoconical or            even concave) and set back from the central exit face, here            this face 13 is an annular surface of circular end outline            (external perimeter) passing through the end A1 and is            furthermore defined by another characteristic point I,            details of which are given below;    -   a cavity 10 a, of axis of revolution coincident with the axis        Oz, comprising:        -   a bottom 110 composed of the entrance face 11, here extended            by a flat 11 a forming an annular surface of circular end            outline (the external perimeter) and also defined by an end            E′ (R_(E′), depth h_(E′)); and        -   an entrance lateral surface 14, flared in the direction of            the entrance of the coupler, comprising three frustroconical            surface portions that are joined by their ends, the small            diameter of one defining the large diameter of the other,            said frustroconical surface portions having axes of            revolution that are aligned on the axis Oz, the intersection            of these three portions with the cross-sectional plane            defining three linear segments in the positive quadrant of            the cross-sectional plane;        -   the first segment 14 a (the furthest removed from the axis            Oz) is connected to the end E′ of the flat (or as a variant,            to the entrance central face E in the absence of a flat) and            passes through the end C₁ (R_(C1), z_(C1)), which is            therefore the closest to the entrance of the coupler for            this first segment;        -   the second segment 14 b is connected to the first segment 14            a and preferably passes through an end point C2 (R_(C2),            z_(C2)), the closest to the entrance of the coupler for this            second segment, the second segment 14 b preferably being            longer than the first segment;        -   and here the third segment 14 c, which is shorter than the            others, terminates on the axis X which passes through the            end C (R_(C), 0); and    -   a peripheral reflective surface 15, encircling the lens and the        cavity, of axis of revolution coincident with the axis Oz, able        to totally internally reflect rays, called oblique rays,        refracted by the entrance lateral surface 14, said peripheral        reflective surface 15 extending beyond the entrance face 11 in        the direction of the exit of the optical coupler, from its        lowest end C as far as its highest end D (R_(D), z_(D)).

The injection system 1000 also comprises an optical collector 20 ofcentral axis coincident with the axis Oz, here axisymmetric (but as avariant it could be substantially oval or hexagonal) and ofmillimeter-size radial extent R_(INT), said optical collector 20comprising:

-   -   optical fibers 20 defined by a given numerical aperture NA here        equal to 0.5 and defining a collecting surface 20 a;    -   and comprising a jacket 21, taking the form of a metal ring,        details of which will be given below, having a given end surface        21 a,    -   the central exit face and the peripheral exit face being spaced        apart from the collecting surface 20 a, the central distance        e_(F) on the axis Oz between the optical collector 20 and the        central exit face 12 being nonzero and smaller than 0.6 mm.

The dimensions of the design of the optical coupler 1 preferably meetconstraints related to the plastic injection molding step: entranceangle β>2° for the demolding. The minimum draft is preferably threedegrees for the walls.

The optomechanical system 1000 furthermore comprises a stop surface 40against which the end surface 21 a abuts.

The stop surface 40 is here joined to the peripheral exit face 13,opposite the central exit face. The jacket 21 a is in abutment over awidth BB′ larger than 0.4 mm.

The stop surface 40 is flat and axisymmetric, annular or as a variantfrustroconical (flared in the direction of the exit of the system).

Here more precisely, the transparent body (therefore the coupler 1)comprises an axisymmetric ramp 16 that here is frustroconical and flaredin the direction of the exit of the system (or as a variant it couldhave any other type of symmetry about the axis Oz) preferably such thatthe exit angle β′≥20° in order to meet demolding constraints.

In the positive quadrant, the following are worth noting:

-   -   the internal edge B of the stop surface 40;    -   the edge F of the end surface 21 a of radial extent R_(INT), in        other words, the external edge of the collecting surface 20 a;    -   the external edge B′ of the stop surface 40 (making contact with        the external outline of the end surface 21 a); and    -   the representative point M (R_(M), h_(e)) on the ramp 16 and of        the same extent in Z as S.

As a variant, it would be tolerable for the end outline A1 of theperipheral exit face (not to be circular, likewise for B) in order toprevent light rays refracted in this extreme zone from entering into thecollector or even to prevent this extreme zone from receiving few or anylight rays.

Thus, the zone between M and B, which here is frustroconical, and evenbetween A1 and M, may in particular in fact be any shape (but preferablyremains demoldable).

The end surface 21 a of the jacket 21 preferably extends beyond the stopsurface 40. Here the end surface 21 a apertures (therefore masks) theoutermost fraction of the peripheral exit face 13, between I (whichfaces F) and A1, here 0.4 mm in width.

Thus, the zone between I and A1 may as a variant in particular be anyshape (but preferably remains demoldable) that does not reinjectparasitic light rays into the collector (i.e. light rays that are notcollimated enough or that are a source of spatial nonuniformity).

The injection system 1000 also comprises a member 30 for aligning theoptical collector 20 with the optical coupler 1, here integrally formedwith the optical coupler 1 (one part) and described below.

The following table collates the coordinates of noteworthy points of thecoupler, of the aligning member and of the stop surface.

X (mm) Z (mm) Entrance LED 0 −0.24 E 0 1.41 E1 1.33 1.63 E′ 1.40 1.63 C1.58 0.00 C1 1.53 1.13 C2 1.56 0.17 D 3.11 2.73 Exit S 0 3.86 I 2.503.53 A 1.37 3.53 A1 2.90 3.53 B 3.07 4.43 M 3.00 3.86

Namely, with a tolerance of ±100 μm related to the plastic injectionmolding process:

X (mm) Z (mm) Entrance LED 0 −0.2 E 0 1.4 E1 1.3 1.6 E′ 1.4 1.6 C 1.60.0 C1 1.5 1.1 C2 1.6 0.2 D 3.1 2.7 Exit S 0 3.9 I 2.5 3.5 A 1.4 3.5 A12.9 3.5 B 3.1 4.4 M 3.0 3.9

The following table summarizes key optimal parameters of the system 1000(in mm):

H 3.9 W (2R_(D)) 6.2 e_(i) 0.2 e_(f) 0.6 R_(INT) 2.5 R_(A1) 2.1 R_(A)1.4 R′₁ 0.1 R₁ 1.3 R_(B) 1.5 R_(C) 1.6 Height of the ramp 16 0.9 BB′1.07

The equation of the surface of the entrance face 11 is written:

${z(r)} = {\frac{r^{2}}{R\left( {1 + \sqrt{1 - {\left( {1 + k} \right)\frac{r^{2}}{R^{2}}}}} \right)} + {A_{4}r^{4}} + {A_{6}r^{6}} + {A_{8}r^{8}} + \ldots}$

The optimal coefficients are defined in the following table:

Convex entrance face conical constant (k) R (mm) A₄ A₆ A₈ Aspheric 04.50 0.01 −0.001 0 coefficients

The equation of the surface of the exit central face 12 is written:

${z(r)} = {\frac{r^{2}}{R\left( {1 + \sqrt{1 - {\left( {1 + k} \right)\frac{r^{2}}{R^{2}}}}} \right)} + {A_{4}r^{4}} + {A_{6}r^{6}} + {A_{8}r^{8}} + \ldots}$

The optimal coefficients are defined in the following table:

Exit central face conicaI R in constant (k) mm A₄ A₆ A₈ Aspheric 0 3.000 0 0 coefficients

The peripheral reflective surface 15 gets further away from the entrancelateral surface 14 and from the entrance face 11 in the direction of theexit of the coupler 1. It is preferably of maximum extent z_(D) along Ozsmaller than the extent z_(A) of the central exit face 12 or of theextent Z₁ and/or Z_(A1). It is larger than H/2. The minimum distanceh_(m), called the material entrance distance, between said peripheralreflective surface 15 and the peripheral exit face 13 is larger than 0.8mm, here the distance between D and A1. The equation of the peripheralreflective surface 15 is written:

${z(r)} = {\frac{r^{2}}{R\left( {1 + \sqrt{1 - {\left( {1 + k} \right)\frac{r^{2}}{R^{2}}}}} \right)} + {A_{4}r^{4}} + {A_{6}r^{6}} + {A_{8}r^{8}} + \ldots}$

The optimal coefficients are defined in the following table:

Peripheral reflective surface conical Radial constant extent (k) (R inmm) A₄ A₆ A₈ Aspheric −1 1.25 −0.00569 0.0001373 0.00002663 coefficients

The light source 50 is a light-emitting diode providing a Lambertianemission (in the far field) and having a square emissive zone 51 ofwidth L equal to 1 mm, said diode being centered on the axis Oz andsurmounted with dome-shaped primary optics 52, fastened (source via abase 53) to the main face of a carrier 60 that is a printed circuitboard that is preferably made of metal in order to promote thermaldissipation of heat via thermal conduction.

This is for example the Luxeon Rebel ES (ref. LXW8-PW35) from PhilipsLumileds, the nominal light flux of which at 25° and 350 mA is 114 lmfor a color temperature of 3500 K. The distance between the dome 52 andE is 170 μm, and the distance between the dome and C is about 300 μm.The dome is very largely inserted into the cavity 10 a so that theoptical coupler can recover a maximum of light rays.

The entrance face 11 and the central exit face 12 are able to orient orto maintain light rays, called central light rays, that are refracted bythe entrance face and the central exit face, toward or in the numericalaperture NA.

The peripheral reflective surface 15 and the peripheral exit face 13 areable to orient or to maintain light rays, called oblique light rays,that are refracted by the entrance lateral surface, toward or in thenumerical aperture NA. The end D is as high as possible in order torecover the rays as best as possible.

FIG. 6 illustrates the centered point response of the optical couplerbased on twelve light rays every 7° originating from the LED, obtainedby simulating the optical system with the software package LightToolsfrom Synopsis.

The properties of the central and lateral rays are indicated in thefollowing table:

Central rays Angle of attack relative to Z (°) Angle of Bottom ofinjection the entrance Central Peripheral Reference relative to Z (°)cavity exit face exit face Ry1 0 0.000 0.000 — Ry2 7 3.419 1.496 — Ry314 6.633 2.659 — Ry4 21 9.365 3.014 — Ry5 28 11.125 1.630 — Ry6 3510.809 — 17.343 Lateral rays Angle of attack relative to Z (°) Angle ofEntrance Peripheral injection lateral reflective Peripheral Referencerelative to Z (°) surface surface exit face Ry7 42 55.188 10.857 17.421Ry8 49 64.777 10.705 17.172 Ry9 56 68.619 8.432 13.479 Ry10 63 72.6696.893 10.998 Ry11 70 76.874 5.677 9.046 Ry12 77 79.231 2.642 4.201

It will in particular be noted that the ray Ry6, refracted by the flat11 a then from the peripheral exit face 13, is deflected from the axis Zand arrives at the surface 20 a of the optical collector at the samepoint as the ray Ry8 that, in contrast, is an oblique ray that isdeflected toward the axis Z. Moreover, the ray Ry7 is one of the lastoblique rays entering into the optical collector 20. This mixing affectsthe spatial uniformity of the light flux injected into the collector.

FIG. 7 shows the path of a few representative lateral light raysoriginating from a centered point source Lo.

Ry′1, emitted at an angle θ′, is received by the collector 20. Ry′2 isalso received by the collector 20. Three intermediate lost rays Ryp arealso shown, these rays passing into the flank of the body 1 or arrivingat the jacket 21 projecting from the collector 20.

FIG. 8 shows the illumination map (illumination in lux) as a function ofthe radial position (in mm), said map being simulated at the collectingsurface 20 here of radius R_(INT) equal to 2.5 mm with optical fibers of500 μm diameter, and also shows two orthogonal cross sections throughthe illumination map. FIG. 8 is obtained with the software packageLightTools.

The illumination is uniform over all of the collecting surface. The fewpeaks observed have a spatial dimension that is so small relative to thesize of the core of the optical fibers that they average out on thescale of the diameter of the fiber.

The optical alignment and fastening of the parts 1, 20 are now describedusing FIGS. 2 to 5. The aligning member 30 comprises a cylindricalsleeve of entrance diameter Φ, lateral to the stop surface 40, thatwidens in the direction of the exit and comprising three clamping ribsat 120° 31 a, 31 b, 31 c. The jacket 21 of the collector is crimped(constricted) 21 b over a first length not making contact with theinternal wall 31 a of the sleeve 30, then the jacket widens 21 c(R′_(INT)<R_(INT)) next defining a clamping height over which localcontact is made with the internal wall of the sleeve 32, and emergesfrom the sleeve especially in order to facilitate itsfitting/demounting.

The body of the optical coupler, which extends beyond the opticalcoupler and therefore beyond its optically functional zone, rests on thePCB source carrier 6, 61, via bearing surfaces 34 taking the form of twofins on either side of the lens, the internal faces of which protruderelative to the cavity 10 a and are spaced apart from the peripheralreflective surface 15. These fin 34 comprise two tenons 35 forself-centering on the PCB 6, 61 and knockouts 33 (further from the lensthen the tenons 35) for nut 36 and bolt fastening to the PCB 6. Fourreinforcing ribs 37 are added between the sleeve 30 and the fins 34.

The collector 20, 21 is defined by the dimensions specified in thefollowing table (inside diameter and outside diameter with the jacket21).

Inside diameter (mm) Outside diameter (mm) Non-crimped zone 5.85 8Crimped zone 5 7.15

Optical measurements are carried out in the location of the collectingsurface using an integrating sphere.

An LED is used, namely the Luxeon Rebel ES (ref. LXW8-PW35) from PhilipsLumileds, the nominal light flux of which at 25° C. and 350 mA is 114 lmfor a color temperature of 3500 K. With the coupler 1′ a flux of 61 lmis obtained at the collecting surface, i.e. an excellent efficacy isobtained. The collector is a bundle of optical fibers of 500 μm diameterand 75 in number that organize as they exit the jacket into an injectionribbon of optical fibers, here forming a layer. R_(INT) preferablyranges from 2.2 mm to 2.5 mm. In the injection ribbon thecenter-to-center distance between two neighboring optical fibers is forexample 0.67 mm. The empty space between two neighboring optical fibersis for example 0.18 mm.

The injection ribbon (at the exit of the jacket 21) opens onto the thinlight-extracting medium (not shown) that is here a light-emitting fabric(here a white, patternless fabric) that comprises a woven textile formedby the optical fibers of the injection ribbon woven into a textile madeof 167 dtex polyester (24%) and PMMA (76%) fibers, the external surfaceof said optical fibers being abraded, in order to scatter the light, andwoven into a textile.

The chosen extracting surface has an optical-fiber density of 15fibers/cm and is rectangular (29.7 cm×10 cm) and 0.5 mm in thickness. Itis a question of the white Lightex® product from Brochier Technologies.

More precisely, the injection system 1000 is duplicated on the twoopposite lateral edges of the extracting surface by placing thus twosystems on each edge. The light-emitting fabric is arranged on a (BA13)plasterboard (preferably) on the white side. The luminance measured isabout 1400 Cd/m².

Moreover, the spatial uniformity of the luminance is excellent becausethe luminance variation coefficient, given by the formula σ_(L)/<L>,where σ_(L) is the standard deviation of the luminance normal to theboard and <L> the average luminance normal to the board, is lower than20%. This luminance variation coefficient is calculated from luminancephotographs of an elementary surface of 1 cm² taken with agoniophotometer such as the Lumicam device from Instrument Systems, saidphotographs being repeated over the entire area of the textile.

Alternatively (or cumulatively) the injection ribbon of optical fibersmay the adhesively bonded to or preferably inserted into a transparent(white or optionally tinted) film, especially made of glass and/orplastic (polymethyl methacrylate (PMMA), polycarbonate (PC) orpolyurethane (PU)), coupled to the injection ribbon and comprising meansfor scattering light.

FIG. 9 illustrates a partial longitudinal cross-sectional view of anoptical coupler 1 a of an opto mechanical system 2000 according to asecond embodiment of the invention, differing above all by the concaveshape of the peripheral exit face 13 a that is joined to the centralexit face and extends (without discontinuity) thus as far as the stopformed by internal edge B. The point M is preferably arranged under thejacket of the collector and the point I is preferably set back relativeto the point S.

In this embodiment the peripheral exit face 13 a is also considered tocomprise a part 16 a between M and A2 leading as far as the stop surface(edge B merged with A2).

Moreover, the jacket 21 of the collector has a (beveled) frustroconicaloutside edge 21 a bearing against the stop surface 40 that is herefrustroconical.

FIG. 10 illustrates a schematic view of the entrance of an opticalcoupler of an optomechanical system 3000 according to a third embodimentof the invention in which the aligning member 30′ and the opticalcoupler 1′ are two separate parts.

FIG. 11 illustrates a (partial) longitudinal cross-sectional view of theoptomechanical system 3000 of the third embodiment of the invention.

The optical coupler 1′ is equipped with four feet 17′ for theself-centering, said feet optionally being force-fitted, by virtue oftheir conical shape, into the PCB source carrier 60 that is drilled forthis purpose (through- or blind holes 61).

The aligning member 30′ rests on a lateral extension 40′ of the coupler1′ in the vicinity of the stop surface 40, said extension being locatedbetween the points J and G. The coupler 1′ has a straight or obliqueflank GH. The aligning member 30′ extends along the flank (against it orspaced apart therefrom) as far as the PCB board 6 and then comprises oneor more fins 34′ equipped with knockouts 33′ for fastening (by screw 36,etc.) to the PCB 6. The aligning member 30′ also blocks thepre-positioned optical coupler 1′.

FIG. 12 illustrates a partial schematic cross-sectional view of theoptomechanical system 4000 according to a fourth embodiment of theinvention in which the aligning member 30″ and the optical coupler 1″are two separate parts.

The ramp 16′ from A1 to the edge B of the stop surface 40 belongs to thealigning member 30″. Beyond A1 the coupler is extended in the form of alobe. The peripheral exit face 13 is extended by a bearing surface 19for the aligning member.

To fit it, the beveled edge (flank GH) of the lens slides over a smoothrib of the aligning member before lodging in its housing.

The aligning member 30′ extends as far as the PCB board 6 via one ormore fins 34′ equipped with:

-   -   a tenon-type self-centering system 35′; and    -   knockouts (not shown) for fastening (by screw) to the PCB 6.

1.-25. (canceled)
 26. An illuminating system, comprising: a light sourceconfigured to emit light; an optomechanical system optically coupled tothe light source, said optomechanical system comprising an opticalcoupler that comprises a body of axis Oz, O being a center of anentrance of the optical coupler, including integrally formed: a lens ofaxis coincident with the axis Oz, of maximum width W, the lenscomprising a convex entrance face of radial extent R1; a convex centralexit face, defined by a central extent H, on the axis Oz, and of radialextent R_(A); and a peripheral exit face that comprises a part joined tothe central exit face, said part being flat or concave or frustroconicaland flared in the direction of an exit of the optomechanical system; acavity, of axis coincident with the axis Oz, comprising a bottomcontaining the convex entrance face, and comprising an entrance lateralsurface; a peripheral reflective surface, encircling the lens and thecavity, of axis coincident with the axis Oz, able to internally reflectlight emitted by the light source and refracted by the entrance lateralsurface, said peripheral reflective surface extending beyond the convexentrance face in a direction of the exit of the optical coupler; anoptical collector of axis coincident with the axis Oz, with a collectingsurface, facing the convex central exit face, of millimeter-size radialextent R_(INT), and a numerical aperture NA smaller than 1, the opticalcollector comprising a jacket having an end surface, the convex centralexit face and the peripheral exit face being spaced apart from thecollecting surface, the optical collector comprising a bundle of opticalfibers to transmit said light; and an aligning member for aligning theoptical collector with the optical coupler, the optical coupler and thealigning member being integrally formed or being indirectly or directlyfastened together, a central distance e_(F) on the axis Oz between thecollecting surface and the convex central exit face being nonzero andsmaller than 5 mm, and the optomechanical system comprising a stopsurface against which the end surface abuts, wherein the end surface ofthe jacket extends toward the axis Oz beyond the stop surface, and theend surface is facing the peripheral exit face; a light-extractingmedium optically coupled to said optomechanical system to transmit lightoutputted by the optomechanical system, and a carrier configured tosupport said light-extracting medium.
 27. The illuminating system ofclaim 26, wherein the carrier is plasterboard, a transparent board or atranslucent board.
 28. The illuminating system of claim 26, wherein thelight-extracting medium comprises a ribbon of optical fibers, or alight-emitting fabric comprising a woven textile including opticalfibers woven into a textile, or a fibrous structure, or asemitransparent or transparent sheet or film coupled to an injectionribbon made of optical fibers, said film comprising a system forscattering light.
 29. The illuminating system of claim 26, wherein thelight source is a light-emitting diode.
 30. The illuminating system ofclaim 26, wherein R_(INT) is smaller than 3.0 mm.
 31. The illuminatingsystem of claim 26, wherein the optical coupler is defined by thefollowing dimensions: 1.88R_(INT)<W<3.1R_(INT);0.41R_(INT)<R_(A)<0.68R_(INT); and 0.4R_(INT)<R₁<0.66R_(INT).
 32. Theilluminating system of claim 26, wherein the optical coupler is definedby the following dimensions: W smaller than 10 mm; H smaller than W;R_(A) larger than 1.2 mm and smaller than 1.6 mm; R1 larger than 1.2 mmand smaller than 1.6 mm; and hE′, maximum depth of the bottom largerthan 1.4 mm and smaller than 1.8 mm.
 33. The illuminating system ofclaim 26, wherein the stop surface is frustroconical and the end surfacehas a complementary shape to the stop surface.
 34. The illuminatingsystem of claim 26, wherein on at least one surface portion closest tothe bottom of the cavity, the entrance lateral surface is frustroconicaland flared in the direction of the entrance of the optical coupler. 35.The illuminating device of claim 26, further comprising a source carrierto support the light source, said source carrier and said optomechanicalsystem being supported by the carrier.
 36. The illuminating device ofclaim 26, wherein the width W is of subcentimeter-size.
 37. Theilluminating device of claim 26, wherein H is smaller than W.
 38. Theilluminating device of claim 26, wherein the light-extracting medium hasa thickness smaller than 5 mm.